Chè molti son che dicono, che senze essere stati con maestri hanno imparato l’arte. Nol credere, chè io ti do l’essempro di questo libro : studiandolo il dì e di notte, e tu on ne vegia qualche pratica con qualche maestro, non ne verrai mai da niente, nè che mai possi con buon volto restare fra i maestri.
-Cennino Cennini. Chapter CIV, Il libro dell’arte: o, Trattato della pittura. Firenze: Editzione F. LeMonnier, 1859. page 69.
There are many who say that they have mastered the profession without having served under masters. Do not believe it; for I give you the example of this book: even if you study it by day and by night, if you do not see some practice under some master you will never amount to anything, nor will you ever be able to hold your head up in the company of masters.
-Cennino Cennini. Chapter CIIII, Il libro dell’arte (The Craftsman’s Handbook). Daniel V. Thompson (trans.). Dover reprint, 1960. page 64.
It is the end of the semester–a time for a little celebration, a little relaxation, and a lot of reflection.
Even as the end of the semester became busier and busier, we were never long without an art project to complete.
Tech & Structure integrated our final unit–Paintings–with yet another project: to make a reproduction of a tempera painting on panel in the Met’s collection. As we learned about the construction of panel paintings with Jean Dommermuth, we worked with conservator Karen Thomas to go through the initial steps of preparing our very own panels.
During this process, we read both Cennino Cennini’s Libro dell’Arte, translated by Daniel Varney Thompson, as well as Thompson’s work The Practice of Tempera Painting: Materials and Methods.
Interestingly, Thompson viewed the replication of Cennini’s craft instructions to be crucial to his translation work, and for eighteen years he studied Cennino–all the while taking the above quote to heart. As a professor at the School of the Fine Arts at Yale, he incorporated a study of the text with practical instruction (Thompson, ix), much as we did during our paintings unit!
First we were given small–approx. 5″x5″–thin squares of wood to work on, with a mind to graduating to the bigger panels for our final project.
To prepare the panel, we first sized it with a rabbit skin glue. This can be bought as pellets or powder, but ours was dissolved in water from large chunks. The size prevents the later applications of gesso from sinking into an overly absorbant panel.
Then we mixed our “Bologna chalk” (hydrated calcium sulfate-carbonate) into the glue to create our ground. Although Cennino differentiates between gesso grosso (the course anhydrite form of calcium sulphate made by roasting the raw gypsum) and gesso sottile (gypsum which is slaked–hydrated–by soaking in water and filtering through a cheese cloth), we did not give thought to that here.
The photos below show the amorphous formations of unslaked plaster. Source: The Techniques of Raised Gilding, by Jerry Tresser.
The photos below show the needle-like structures of slaked plaster. Source: The Technique of Raised Gilding, by Jerry Tresser.
Also, traditional Italian “gesso” ground would be made of calcium sulfate, not including calcium carbonate, as with the “Bologna chalk” product.
After the application of the ground, it was vigourously sanded to achieve the most perfectly smooth surface possible.
If the panel was to be gilded, as mine was, bole–a type of clay traditionally used for “water gilding“–was applied over the ground. We used a premixed bole (Lefranc-Bourgeois, extra-fine Gilder’s Clay Base) in a wet-paste form, composed of Armenian clay and water. This was blended with rabbit skin glue or gelatin before application.
I messed up at this stage and applied bole to the entire surface, not merely to the ones to be gilt. Later I roughly drew the design and sanded back into the panel to remove the bole from where the design was to be painted. The traces of bole are still visible within the white field.
Some of us experimented with either pastiglia or oil gilding techniques at this stage.
I was glad to have gained some practice gilding before moving on to our big panel projects. It was quite frustrating at times, especially with the air-conditioning blowing the leaf around. But considering that Cennino posited a very strict time-table for gilding when the humidity was just right and that the gold leaf produced today is very much thinner than the hand-pounded variety, I tried to hold out judgements on the difficulty of the project.
The gold we used for both panels was produced by Giusto Manetti Battiloro (or, Giusto Manetti Goldbeaters). As company reconstructed after the 1944 American bombing of Florence, it is still considered to be one of the city’s oldest companies (Source: manetti.it).
Here is a short, wordless documentary produced by Andrea Mariotti for GM Battiloro. The beginning shows how a gold leaf booklet is produced from an ingot, but it also shows a master gilder at work–which my classmates and I certainly appreciate after experiencing just how hard it is to handle this gold leaf.
After the gilding was complete, the surface was burnished with any number of agate tools of different sizes. It was often very challenging to burnish around very pronounced pastiglia details! A few of mine even broke off when I rewet the bole and ground under the leaf; the moisture weakened the areas of pronounced topography, which pared off when I aggressively burnished it.
Next I moved on to my large panel, which luckily did not have any pastiglia!
I chose a Greek icon depicting the head of the Virgin that was on display amongst other Late Byzantine objects at the Met.
After grounding, gilding, and drawing, the next step was to grind our pigments.
Did we poison ourselves with imitation vermillion, or just make messes? Was my painting recognizable as the Virgin Mary, or was it horribly Giménian?
Read on to find out…!